1. Field of the Invention
The invention is directed to tooling for machining operations and, more particularly, directed to a clamping device for securing a tool to a toolholder body.
2. Description of Related Art
Clamping systems that utilize a collet or similar device for securing a tool to a machine tool or intermediate toolholder are well known. The collets generally comprise a tubular body formed from a plurality of elongated, flexible fingers. The fingers are separated by longitudinal collet slots that impart a degree of radial flexibility to the collet, which allows the collet to selectively grip the shank of a cutting tool, such as a drill bit. The collet is inserted in a complementary-shaped opening in the toolholder so that an end of the collet is accessible through the opening in the toolholder. Such systems generally require side or rear actuation of the collet by a screw or cam to cause the collet to radially compress and clamp around a shank of the tool without direct contact to the radially flexing portions of the collet. Such systems may also require the collet to be physically moved within the toolholder.
Accordingly, typical prior art systems require a complex construction of components to actuate the collet, which may be cost prohibitive and be too large depending on the tooling application and require complicated machining of the toolholder itself. The collet itself may not be accurately positioned within the toolholder and gage height of the collet may be difficult to maintain during assembly, maintenance, and use. Movement and wear of the collet may reduce the gripping force and loosen the clamping connection between the collet and the tool, leading to inaccuracies in machining operations. Further, due to the high clamping forces involved, the shank of the tool may become stuck within the toolholder and difficult to remove without disrupting the position of the collet.